They made W2 heads for a 440 big block? Never heard of that.

Or would that be some sort of model number for the station wagon?

ONLY an .87 t-bar???? I'd go with a 1" at least and probably a 1 1/4 with a 440 big block, depending if that is really the engine size. Or a 1" min. with a 340ish small block.

If you REALLY want an .870 t-bar, then get a much heavier anti-sway bar, that way the .870 t-bar will allow for a softer/better/smoother ride, and the heavier front anti-sway bar and matched rear bar will allow for more spirited driving of the curvies, been there, done it that way.